Pressure roller device

ABSTRACT

A device for smoothing the inner surface surrounding a bore has a core which can be rotated about an axis and a ring which surrounds the core and is fast therewith. The ring is composed of two or more circumferentially adjacent sections which are mounted so that they can be radially displaced relative to one another and the axis of rotation of the core. The radial thickness of these sections is less in the region of the juncture than intermediate these regions. Roller elements of cylindrical configuration are carried by the outer periphery of the ring and, when the device is inserted into a bore, will contact the inner surface surrounding the same and smooth it during rotation.

United States Patent Kunze [54] PRESSURE ROLLER DEVICE [72] Inventor: Bernhard Kunze, Erkelenz, Germany 7 [73] As'signee: Wilhelm Hegenscheidt Kommanditgesellschaft, Erkelenz, Germany [22] Filed: July 7,1971

21 Appl. No.: 160,301

[52] US. Cl ..72/120, 72/126 [51] Int. Cl. ..B21d 3/02 [58] Field of Search ..72/113, 126, 120; 29/90 R [56] References Cited UNITED STATES PATENTS I 751731 2/1904 Hill "172/126 6/1965 Adam ..72/126 [451 Dec. 12,1972

Primary Examiner-Milton S. Mehr Attorney-Michael S. Striker [57] ABSTRACT A device for smoothing the inner surface surrounding a bore'has a core which can be rotated about an axis and a ring which surrounds the core and is fast therewith. The ring is composed of two or more circumferentially adjacent sections which are mounted so that they can be radially displaced relative to one another and the axis of rotation of the core. The radial thickness of these sections is less in the region of the juncture than intermediate these regions. Roller elements of cylindrical configuration are carried by the outer periphery of the ring and, when the device is inserted into a bore, will contact the inner surface surrounding the same and smooth it during rotation.

10 Claims, 4 Drawing Figures SHEET 1 OF 2 PATENTEU nu: 12 I972 FIG.2

INVENTOR Bernhard KUNZE his ATTORNEY PATENTEDDEB I 2 1912 sum 2 or 2 FIG. 4

INVENTOR Bernhard KUNZE his ATTORNEY PRESSURE ROLLER DEVICE BACKGROUND OF THE INVENTION The present invention relates generally to a pressure roller device and more particularly to a device for smoothing the inner surface surrounding a bore. Still more specifically, the invention relates to such a device which can be used advantageously-although not exclusively-in bores into the interior of which a hub or similar projection extends, so that an annular space is provided between them whose larger diameter, that is the outer circumferential surface bounding this annular gap, must be smoothed and made very even.

Devices for the general purpose here in question, namely the smoothing of a surface bounding a bore, are already known. In fact, a-variety of such devices is known including some wherein a core carries roller elements which exert a pressure upon the inner circumferential surface bounding the bore when the core with the roller elements is rotated, and which thereby smooth this surface. For the most part the known devices operate with conically configurated rollers which are supported on a conical core and which can be shifted axially of the core in order to vary the pressure with which they abut against the surface to be smoothed, or in order to adjust the device for bores of different diameters. Devices of this type are for instance disclosed in German patents No. 695,] l l, 875,903 and German patent application P 25,382D.

Generally speaking, these devices have certain drawbacks. In particular, they cannot operate while being continuously advanced axially of the bore, and in addition thereto they cannot be readily and precisely adjusted to a given diameter of a bore. Also, before it can be determined whether the surface of the bore has been smoothed to the desired extent, so that the bore has a desired diameter, the deviceany of the devices of the prior art-must first be removed from the bore before the latter can be measured. Only then is it possible to determine whether further operation with the device is unnecessary, or whether the device must be adjusted in order-to increase or decrease the pressure with which its rollers contact the inner circumferential surface of the bore. In addition, when the device is withdrawn from the bore the rollers tend to form visible stripes on the inner circumferential surface of the bore, resulting from the fact that the plastically deformablematerial in which the bore is formed is under tensions which tend to equalize and thereby permit the material of the work piece to elastically return inwardly to its original position behind the withdrawing rollers.

Another type of device for this purpose is so constructed that the rollers do not have line contact with the inner circumferential surface of the bore, as do those of the previously discussed device, but instead have only point contact. In these devices the material of the work piece in which the bore is formed is subjected at the point of contact with the rollers to pressures which stress it to the elastic limit, whereas the circumferential surface of the roller which is inclined to the axis of the bore smooths the flowing material and imparts asmooth highly polished surface to the inner circumferential surface bounding the bore, in effect copying 'their own outer circumferential surface configuration. These latter types of devices, of which those described in U. S. S. R.- patent 161,638, Swiss patent 265,905 and German patent 955,020 are representative, can be advanced in the bore during operation.

All of these prior-art devices, however, completely fill the cross-section of the bore and in most instances there is such a significant spacing between the end of the device -that is the leading end which is inserted first into the boreand the rollers that it is not possible to treat with such devices blind bores because the leading end of the device would abut against the closed end of the bore while the rollers are still spaced by a significant distance from this closed end so that the circumferential surface of the bore intermediate the rollers and the closed end could not be treated. Evidently, this is true also of an annular space which is blind.

SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to provide a device of the type under discussion which is not possessed of these disadvantages.

More particularly it is an object of the present invention to provide such a device which is capable of Iongitudinal advancement in the bore during operation, and which is further capable of fully satisfactorily smoothing and treating the circumferential surfaces of even blind bores, regardless of whether they are of conventional type or of annular type. The latter is for instance found in brake drums for automotive vehicles.

An additional object of the invention is to provide such a device having an operating range which is relatively large, which can be controlled, adjusted and reproduced without difficulties.

A concomitant object of the invention is to provide such device which is relatively simple in its construction and therefore reliable in its operation.

In pursuance of the above objects, and of others which will become apparent hereafter, one feature of the invention resides in a device of the character described, particularly for the purpose of smoothing the inner surface surrounding a bore, which comprises, briefly stated, a core adapted to be rotated about an axis, and a ring surrounding and fast with the core. According to the invention the ring comprises at least two circumferentially adjacent sections which are radially displaceable relative to the axis and of lesser radial thickness in the region of their junctures than intermediate thereof. A plurality of roller elements are carried by the outer periphery of the ring for rolling displacement about axes which at least substantially parallel the axes, such roller elements being adapted to contact the inner surface surrounding a bore and to smooth it under exertion of pressure.

By having the radial thickness of the sections be less in the region of their juncture than intermediate this region, the device according to the present invention assures that the rollers of roller elements will contact the inner circumferential surface of the bore in at least two diametrally opposite contact zones in which the rollers are in abutment both with the ring on which they are provided and with the inner circumferential surface of the bore. Intermediate these zones are the zones in which the sections abut one another or adjoin one another, and in which due to the lesser radial thickness of the sections the rollers do not contact the ring and therefore are not pressed with any significant force against the inner circumferential surface of the bore.

Adjustments in the pressure and for bore diameters are effected in the device according to the present invention by the relative radial displacement of the sections carrying the roller elements, whereas this is primarily accomplished in the prior art by axial displacement of the roller elements on a conical core. The device according to the present invention can be constructed lighter, simpler and less bulky than what is known heretofore.

The present invention thus makes it possible to treat the inner circumferential surfaces of even relatively large bores with a light-weight simple device, because the device is configurated in annular form and because no significant components are located in the core of the device itself. A further advantage of the device according to the present invention is the fact that it utilizes very thin cylindrical pressure rollers so that the high specific pressure exerted by the rollers requires only relatively low pressure forces, thereby reducing the danger of a deformation of the work piece being treated.

It is advantageous, according to an embodiment of the invention, that the sections of the ring are connected at one juncture by a pivot joint so that they can pivot about an axis extending in parallelism with the axis of rotation of the core, whereas diametrally opposite this juncture in the region of the other juncture, mechanical or fluid-pressure operated-usually hydraulically operated-means are provided which radially outwardly displace the sections with reference to one another. Either mechanical or hydraulic means are suitable, as already indicated, and both types have their advantages and may be utilized in given circumstances.

According to a further embodiment of the invention the outer circumferential surface of the ring may be conical in axial direction with the largest diameter directed towards the work piece (in practice in the range of 0.3 mm to I mm length). This positions the roller elements in such a manner which, according to experience gathered, affords the best rolling and smoothing effect on the surface of the bore.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims.

The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross-section through a device according to the present invention;

FIG. 2 is a fragmentary longitudinal section of FIG. 1, taken on line I-I of FIG. 1;

FIG. 3 is a partly sectioned end view of the device; and

FIG. 4 is a fragmentary view, somewhat analogous to that of FIG. 3, but illustrating a device utilizing mechanical displacing means instead of hydraulic displacing means as in the preceding embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing firstly the embodiment in FIGS. 1-3 it will be seen that reference numeral 1 identifies a ring element which is provided in its inner circumferential surface with a circumferentially extending undercut dovetailed cross-section groove 2, which receives a correspondingly configurated projection on a core 3 whereby the latter is connected with the ring 1. An intermediate ring 4 is provided which, in conjunction with screws 5, presses and holds the ring 1 on the core 3. The core 3, the ring 1 and the intermediate ring 4 are connected and subdivided radially into two identical sections which can be pivoted about the bolt 6 and which are drawn together by a spring 7 cooperating with a screw or bolt 8 having a head against which the spring 7 abuts with the other end of the spring abutting against the bottom wall of a recess provided in one of the sections as illustrated in FIG. 1. Thus, the two sections can be pivoted in radial direction with reference to one another about the longitudinal axis of the pivot pin or bolt 6, that is about an axis which extends in parallelism with the center axis of the core 3.

Diametrally opposite the bolt 6 is provided displacing means capable of displacing the sections with reference to one another in radially outward direction. In FIGS. l-3 this displacing means is in form of a hydraulic piston 10 provided in one section and abutting against the other section of the core 3. A bore 11 is provided communicating with the chamber formed in the one section and accommodating the piston 10, this chamber being identified with reference numeral 9, and hydraulic pressure fluid may be supplied to the chamber 9 through the bore 11 for the purpose of displacing the piston 10. In the illustrated embodiment it will be assumed that the chamber 9 and the bore 11 are filled with high viscid oil which can be pressurized by a screw 12 (or more than one) to impart to it hydrostatic pressure. In the illustrated embodiment the screw 12 is provided with an interior hexagonal recess 13 and an indicia mark 14, being located within a circular scale 15 provided on the core 3. Thus, a pressure can be selected in the chamber 9 at will.

A screw 16 provided with a head is located in a recess of one of the sections, similar to the screw 8, and a spring 17 cooperates between the bottom wall of this recess and the head of the screw 18; because the screw 16 extends into the opposite section of the core 3, that is the one provided with the piston 10 (this is not visible because the portion of the screw 16 which extends into this opposite section is hidden behind the piston 10 in FIG. 1) the spring 17 always draws the opposite section against the outer end face of the piston 10.

The outer periphery of the ring element 1 is provided with a plurality of roller elements 19 of cylindrical configuration. They are guided in a race 18 or cage 18 and contact the inner circumferential surface of the bore in the work piece, that is in the manner shown diagrammatically in FIGS. 1 and 3. It is to be noticed in FIG. 1, however, that this contact takes place only in the contact or working zones 20 and 21 because intermediate these zones the sections of the ring 1 are slightly flattened, that is in the region of the juncture of the sections the latter have a lesser radial thickness than intermediate these regions. As a result of this the roller elements 19 which are supported in the cage 18 do not contact the surface of the ring 1 when they reach these regions whichare located intermediate the zones 20 and 21, so that when they enter into these regions they do not exertany significant pressure against the inner circumferential surface of the bore and do not perform any work until they move into the next following one of the zones 20 or 21.

When the screw 12 is threaded deeper into its bore by engagement of the hexagonal recess 13 with a suitable tool, thereby pressurizing the hydroplastic mass in the chamber 9, then the piston moves the two sections of the ring 1 radially apart, so that they pivot about the axis defined by the pin or bolt 6. This causes the rollers 19 tobe pressed against the inner circumferential surface of a bore in which the device is accommodated, but such contact takes place only in the zones 20 and 21 whereas there is no contact intermediate these zones for the reasons mentioned above.

Coming now to the embodiment in FIG. 4 it is pointed out that this corresponds largelyto that of FIGS. 1-3, except that the hydraulic displacing means of the first embodiment is here replaced with a mechanical displacing means. The embodiment of FIG. 4, wherein like reference numerals identify like components as in FIGS. 1-3, comprises a screw 22 which engages with a nut 23. The screw 22 can be turned by a worm and a worm gear 24, and the nut 23 and worm gear 24 are non-rotatably connected by a profiled portion 26 (here of quadratic cross-section). The nut 23 is connected with the core via a screw 27 which extends inwardly from an exposed end face of the section of the core in which the nut is provided. This secures the nut against displacement.

As in the preceding embodiment, the two sections of the body are drawn together by a spring means, here again identified as a package of disk or belvel springs 28, which is mounted on and surrounds the screw 29. It will be appreciated that the worm 25 causes the two sections of the core and of the ring to be radially displaced with reference to one another, or to be drawn together. The marking arrangement discussed with reference to FIG. 3 is here also provided (not illustrated) at an axial end face of the core 3 in order to provide an indication of the radial spreading of the sections of the core 3 when the worm 25 is turned.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a pressure roller device, it is not intended to be limited to the details show, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully and range of equivalence of the follpwin claims.

What IS claimed as new and desired 0 be protected by Letters Patent is:

l. A device of the character described, particularly for smoothing the inner surface surrounding a bore, comprising a core adapted to be rotated about an axis; a ring surrounding and fast with said core, at least said ring comprising at least two circumferentially adjacent sections which are radially displaceable relative to said axis and lesser radial thickness in the region of their junctures than intermediate thereof; and a plurality of roller elements carried by the outer periphery of said ring for rolling displacement about axes which at least substantially parallel said axis, said roller elements being adapted to contact the inner surface surrounding a bore and to smooth it under exertion of pressure.

2. A device as defined in claim 1; and further comprising displacing means for effecting radial displacement of said sections with reference to said axis and to one another.

3. A device as defined in claim 1, wherein said sections have two junctures at diametrally opposite locations; further comprising a pivot connection at one of said junctures connecting said sections for pivotal radial displacement about a pivot axis which at least substantially parallels said axis; and said displacing means being located in the region of the other of said junctures and acting upon both of said sections in a sense displacing them radially about said pivot axis in outward direction.

4. A device as defined in claim 3, said displacing means comprising mechanical displacing means.

5. A device as defined in claim 3, said displacing means comprising fluid-operated displacing means.

6. A device as defined in claim 3, said displacing means comprising hydraulic displacing means.

7. A device ad defined in claim 1, said sections together defining an outer peripheral surface of said ring which is of conical outline in longitudinal direction of said axis.

8. A device as defined in claim I, and further comprising a cage surrounding the periphery of said ring and maintaining said roller elements in predetermined relative relationships.

9. A device as defined in claim I, wherein said roller elements are of cylindrical configuration.

10. A device as defined in claim 8, wherein said race and said roller elements are out of engagement with said ringdue to the lesser radial thickness of said sections, in the regions of the junctures of the sections. 

1. A device of the character described, particularly for smoothing the inner surface surrounding a bore, comprising a core adapted to be rotated about an axis; a ring surrounding and fast with said core, at least said ring comprising at least two circumferentially adjacent sections which are radially displaceable relative to said axis and lesser radial thickness in the region of their junctures than intermediate thereof; and a plurality of roller elements carried by the outer periphery of said ring for rolling displacement about axes which at least substantially parallel said axis, said roller elements being adapted to contact the inner surface surrounding a bore and to smooth it under exertion of pressure.
 2. A device as defined in claim 1; and further comprising displacing means for effecting radial displacement of said sections with reference to said axis and to one another.
 3. A device as defined in claim 1, wherein said sections have two junctures at diametrally opposite locations; further comprising a pivot connection at one of said junctures connecting said sections for pivotal radial displacement about a pivot axis which at least substantially parallels said axis; and said displacing means being located in the region of the other of said junctures and acting upon both of said sections in a sense displacing them radially about said pivot axis in outward direction.
 4. A device as defined in claim 3, said displacing means comprising mechanical displacing means.
 5. A device as defined in claim 3, said displacing means comprising fluid-operated displacing means.
 6. A device as defined in claim 3, said displacing means comprising hydraulic displacing means.
 7. A device ad defined in claim 1, said sections together defining an outer peripheral surface of said ring which is of conical outline in longitudinal direction of said axis.
 8. A device as defined in claim 1, and further comprising a cage surrounding the periphery of said ring and maintaining said roller elements in predetermined relative relationships.
 9. A device as defined in claim 1, wherein said roller elements are of cylindrical configuration.
 10. A device as defined in claim 8, wherein said race and said roller elements are out of engagement with said ring due to the lesser radial thickness of said sections, in the regions of the junctures of the sections. 